The best of last June

Triatoma infestans, Chagas vector This is the conclusion of a report to be published in the June 2008 PLoS Neglected Tropical Diseases journal. The report, by Peter Hotez of George Washington University and the Sabin Vaccine Institute, is a clear indictment of economic disparity in the United States. The bottom line: Many poor Americans are, effectively, living in a poorly managed third world country.

Poor people in the United States are subject to a mostly ignored burden of diseases “caused by a group of chronic and debilitating parasitic, bacterial, and congenital infections known as the neglected infections of poverty.” This is the “developed world” counterpart of neglected tropical disease, as they disproportionately affect impoverished and under-represented
minority populations. According to a report about to be published in PLoS Neglected Tropical Diseases:

The major neglected infections include the helminth infections, toxocariasis, strongyloidiasis, ascariasis, and cysticercosis; the intestinal protozoan infection trichomoniasis; some zoonotic bacterial infections, including leptospirosis; the vector-borne infections Chagas disease, leishmaniasis, trench fever, and dengue fever; and the congenital infections cytomegalovirus (CMV), toxoplasmosis, and syphilis.

These infections are concentrated in poor populations, among people of color, and in the American South with an epicenter around the Mississippi Delta, and in poor urban areas and along the US-Mexican border. Appalachia is another hot spot.

This report uses this this very interesting and alarming pair of maps, previously produced by the CDC:

Figure 1. Location of Counties That Represent Spatial Clusters in Which Poverty Rates Are at Least Two Standard Deviations Higher Than the National Mean. Top: Counties south of the Continental Divide. Bottom: Counties north of the Continental Divide.

There appear to be three important common features among the very long list of infectious diseases impacting these populations. From the report:

(1) their highly disproportionate health impact on people of color and people living in poverty;
(2) their chronic, largely insidious, and disabling features; and
(3) their ability to promote poverty because of their impact on child development, pregnancy outcome, and productive capacity.

It is also noted that while some of the studied diseases are exclusive to recent immigrant populations, most are not associated with immigration. The single most important determinant of these diseases is clearly stated in this report: Poverty.

Depending on which disease is considered, between tens and hundreds of thousands of people are affected. The paper’s authors recommend:

…active surveillance (including newborn screening) to ascertain accurate population-based estimates of disease burden; epidemiological studies to determine the extent of autochthonous transmission of Chagas disease and other infections; mass or targeted treatments; vector control; and research and development for new control tools including improved diagnostics and accelerated development of a vaccine to prevent congenital CMV infection and congenital toxoplasmosis

Hotez, P.J. (2008). Neglected Infections of Poverty in the United States of America.

. PLoS Neglected Tropical Disease, 2(6)